


before you could say 'splish splash'

by mothicalcreatures (laelreenia)



Category: Hunter X Hunter
Genre: Fluff, Injury, Injury Recovery, M/M, Mermaid Killua, Pre-Relationship, heading very swiftly towards relationship, mermaid au
Language: English
Status: Completed
Published: 2019-07-07
Updated: 2019-07-07
Packaged: 2020-06-24 06:56:59
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 6,007
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19718515
Author URL: https://archiveofourown.org/users/laelreenia/pseuds/mothicalcreatures
Summary: Recovering from a run in with a fishing trawler by Whale Island, Merrow!Killua makes friends with a very enthusiastic human boy named Gon.





	before you could say 'splish splash'

**Author's Note:**

> Merrow is used as a gender-neutral alternative to mermaid/merman.

Killua feared humans less than most merrows, mostly due to how he raised. His family was notorious for luring humans to their deaths; his grandfather could take down a whaling vessel with ease and Illumi was particularly adept in getting sailors to drown themselves. Killua, while he had been active in the family business had favored a more hands on approach. He had put an end to that, however, when he’d… aggressively left home. He’d only minorly stabbed Milluki and clawed up his mother’s face.

Having dealt easily with humans before, Killua had perhaps underestimated the severity of the situation when he’d gotten caught up in the net of a fishing boat. His thrashing and clawing had done nothing to help, the netting seemed designed to further ensnare him every time he tried to rake his claws through it to free himself. It was really his fault for not paying better attention to his surroundings, he thought to himself as he was dumped unceremoniously to the deck along with the other fish in the net.

He stayed still, listening to the shouting of the humans on deck, waiting for his opportunity to strike. Waiting for someone to get close enough for him to lunge through the net, he knew he was strong enough to drag the net with him to move. That was his first miscalculation. There was a click and a hiss and Killua was barely able to move fast enough to avoid catching a crossbow bolt somewhere vital.He hissed in pain as the bolt ripped a gash along his hip.

Not waiting for the human who’d fired to reload, Killua lunged towards the edge of boat in an attempt to fling himself back in to the ocean. If it was only the weight of the net he’d had to worry about, he would have made it easily, but the net caught on the rail as Killua went over the side. The net constricted sharply around his already injured tail and Killua let out an unearthly shriek, clawing his way up to hack at the net with his claws and teeth until it finally gave with a tear and Killua dropped back into the water, swimming away as fast as he could.

Killua swam until he was in too much pain to keep going, and then began his search for a cave, where he could recuperate above water. Curling up to rest underwater while injured would be asking to be attacked by a shark or a merrow of that ilk. The first one he found was a bit too close to a beach for his liking, but it would have to do for the time being. He could find a better place once he’d assessed his injuries.

The gash on his tail was right up near his hip and was deep enough that it would probably need bandaging. The injuries from the netting that he remained entangled in were more serious, in his opinion. The netting had already cut into his skin in such a way that Killua didn’t know how he could get it out without causing more damage to himself. He hacked off as much of the excess as he could, but the netting around his big tail fin was just too deeply enmeshed. He’d also lost a piece of his tail fin when he’d torn free of the netting. He’d been in such a frenzy to get free, Killua wasn’t sure if he had inadvertently gashed his tail himself or if it had been torn when he fell free. There was nothing he could do about it at any rate.

Determining that he was in no immediate danger of dying, Killua curled up on the rocky floor of the cave and tried to sleep.

Killua woke to the sound of children shrieking and he immediately tensed, worried he’d been discovered. There were no children in sight, however, he was still alone in the cave. The sounds were probably coming from the beach. Wherever he’d wound up, it was clearly an area inhabited by humans. It may have even been where the fishing boat had originated from.

Giving his injuries a cursory examination again, Killua deemed that he was safe to return to the water without attracting sharks. Submerging in the water was incredibly refreshing, despite the sting of the salt in his wounds. Being above water for so long always made him feel achey and dry. After spending some time circling the area to get his bearings, Killua caught himself something to eat and then settled down in some underwater caves on the other side of the landmass, which he had determined to be a small island.

Over the next few days, Killua remained hidden, staying underwater and surfacing only when he needed to find better plants to bandage his injuries or wanted to catch a particularly tasty kind of frog that he found lived at the waters edge. At times he thought he could sense someone watching him when he was above water, but he could never see anyone.

After spending roughly four days like that,Killua started feeling antsy to get moving again. Although, he doubted how swiftly he’d be able to make an escape should he need to. Being even a fraction of a second too slow could spell his capture should he encounter a family member out hunting for him. It would be Illumi, most likely, and Illumi was much stronger than him. He would make his decision that evening, he decided.

Surfacing just after dusk, Killua began his slow prowl along the edges of the lagoon. The frogs would be emerging soon and it was much more fun to try to catch them once they were out than it was digging them out of their dens.

He could feel that watching presence, but it was just watching, there was no threat to it, so he paid it little mind as he zeroed in on a particularly large frog. Killua’s arm shot out of the water for the frog in a split second, but just as quickly a hand reached out of the foliage and grabbed his wrist before his hand closed around the frog.

Killua froze in fear. Someone who could catch his hand with seeming ease was a much bigger threat than Killua had initially though the watching presence to be. He remained completely still, he needed togauge the situation before he could decide if he needed to fight or just flee. A low hiss escaped him as he tried to calm his racing heart. As he did so the foliage in front of him shifted and revealed the human behind it. It was a boy, probably no older than Killua. Killua snarled, twisted his arm to grab the boys wrist, sinking his claws in as he did so, and dove.

* * *

Gon only barely managed to get a lungful of air before the merrow dragged him under the water. He doubted he could escape, the merrow’s grip on him was like a vice, so Gon focused on holding his breath until they stopped moving. As they slowed to a halt Gon opened his eyes just in time to see the merrow surge back at him and sink his teeth into Gon’s shoulder. Gon gasped, letting out more air than he would have liked before he was able to catch himself, but he clenched his teeth and just held on, if he didn’t struggle or fight back, he’d probably be fine. The merrow just was scared, Gon wanted to _help_ him, not _hurt_ him, but hr needed to see that. Admittedly, his plan probably could have done with more thinking through.

It worked though, the merrow released him, moving back to stare in apparent shock as Gon held his hand out. Gon’s lungs were starting to burn, but he wanted to give it a few more seconds, he still wanted to try to befriend the merrow.

The merrow scowled and then grabbed Gon’s hand before shooting towards the surface.

Gon took a big gasping breath as soon as he broke the surface and he started to swim towards shore, or he tried to, the merrow was still dragging him and didn’t let go until they’d reached a point where Gon could easily climb out.

“You’re an idiot,” the merrow snapped, hauling Gon up onto a large flat rock. “I could have killed you.”

Gon grinned, and then winced when he put his weight on his bad shoulder. “But you didn’t.”

The merrow bristled. “Why would you grab me like that? If you live by the water you should know what merrows are like!”

“I didn’t know how else to get your attention,” Gon said. “You’re hurt, I wanted to help.” He shrugged. “Besides, most of the merrows in this area aren’t particularly vicious. We work with them for the most part and we’ve even got a vet specialist who can help merrows.”

The merrow was silent and just stared at Gon, like he wasn’t sure whether Gon was telling the truth or not.

“Also those frogs you were catching are a protected species,” Gon said, “They only exist here. I didn’t want you getting poached just because you didn’t know.”

The merrow huffed. “Fine, I was going to leave tonight anyway. I’ll catch something on my way then.” He scooted over to the edge of the rock and was about to dive back in but Gon grabbed his hand again.

“Are you sure? I can get the vet to come down tomorrow and look at your tail. She won’t hurt you I promise.”

The merrow’s eyes flicked between Gon and the water. “You should worry about yourself first,” he said, and then dove back into the water. Gon frowned, it wasn’t a no, but it wasn’t a yes either. He’d get the vet to come down tomorrow just in case the merrow was still there.

Despite the fact that Gon had been very quiet scaling the side of the house and crawling in through his window, Mito still caught him when he went into the bathroom to get supplies to treat his shoulder.

She cornered him just as he was leaving the bathroom.

“Gon! Where have you been? I went to check on you and you weren’t in bed!” Mito’s eyes widened when she saw his bandaged shoulder. “What on earth happened?”

“There’s a merrow in the lagoon,” Gon said excitedly. He knew he was in trouble, but still tonight _had_ been very exciting. There were always merrows comingand going around Whale Island, but he’d never actually been up close to one before. 

“Did it attack you? Do we need to tell someone that there’s a dangerous merrow in the area?”

Gon shook his head quickly.“No, no! It’s okay, I just scared him. He’s hurt and really skittish, and also he was eating the frogs, so I waited for him to get his attention so I could talk to him and see if I could help.”

Mito deflated. It was hard to be mad at Gon when he broke rules trying to help others.

Gon rolled his shoulder and winced. “I’ll be okay, Aunt Mito, I promise. Also, please don’t ground me just yet, I promised the merrow Iwould bring the vet down to see him tomorrow. He got caught in a fishing net and now it’s stuck on his fin.”

Mito sighed. “Fine, but _after_ that, you’re grounded.”

“That’s fine!” Gon said, grounding rally just meant more chores. It wasn’t like he wasn’t going to be able do his own things, he’d just have less time for it.

“Get to bed before I change my mind,” Mito replied, then she paused. “And no climbing until your shoulder is healed.”

Gon nodded, that was a fair trade off, he wouldn’t want to be climbing with an injured shoulder anyway. He felt very grateful that Mito hadn’t seen the actual bite marks. They looked pretty bad, but Gon felt confident he didn’t need stitches and he didn’t need his aunt freaking out and rushing him to the doctor for something that would mostly likely be healed in a few days anyway.

The next day Gon was up and at the vet clinic bright and early to see if he could catch Marina because she opened for the day. He knew she was busy, so he didn’t want to take her away from people who had appointments with her, but injured merrow in the lagoon was also a little bit of an emergency situation. At the very least it was time sensitive, because the merrow didn’t seem like he was going to stick around for very much longer, if he hadn’t left already.

However, much to Gon’s chagrin, Marina insisted on looking at his injury before they headed out.

“Merrows have a lot of bacteria in their teeth that we’re not necessarily used to,” Marina scolded. “Beside, what if they had been venomous.”

“He didn’t look venomous,” Gon said. “His coloration was mostly blues and whites. If he were venomous, I think his colors would be brighter than that.”

“That’s…That’s not a hard and fast rule Gon,” Marina said, sighing. “But the bite looks fine, it doesn’t look infected and frankly it’s already well on its way to being healed. It honestly doesn’t look like a day old bite.”

“I heal fast,” Gon said and jumped off the exam table. “Can we go see the merrow now?”

“Yes, let me just tell my aide I’m going out.”

* * *

Killua was baffled by the human he’d dragged into the water. He had seemed completely unfazed by Killua attacking him. Killua hadn’t seen many humans in situations where he wasn’t preparing to kill them,but, still, that didn’t seem like normal human behavior and he stood by his initial assessment that his human was an idiot.

He didn’t leave, however. The prospect of getting the last of the netting removed from his tail was a very enticing one and for all the human had been an idiot for grabbing Killua, he hadn’t tried to hurt him outright. If this was a trap, Killua could probably escape easily, but if it wasn’t… well, he’d get the horrid netting off.

Just as he was considering going out to catch some unfortunate fish, there was a large disturbance in the water and when Killua peeked out of the cave… there was the human again. He waved cheerfully when he saw Killua and Killua swam out and up to the surface.

He reached he surface just a moment before the human did and his eyes immediately shot to the other human who was sitting on the big flat rock they’d sat on the night before.

“That's Marina,” the boy said. “She’s the vet I told you about.”

The other human, Marina, nodded and moved over so that there was more room for Killua to climb up onto the rock.

“You’re safe with us,” she said. “But I will need you to come out of the water to look at your tail.”

Killua eyed her up for a moment, like the human boy, she didn’t feel like a threat, so he swam over and hauled himself out of the water.

Marina took a sharp breath when she saw the state of Killua’s tail. “This is much more than just caught in netting,” she muttered. “Can I ask what happened?”

“I got caught up in the net of a fishing trawler and they decided I’d make good seafood,” Killua said. “Everything’s healing just fine, the only problem is the netting really.”

It was hard not to flinch when Marina picked up his tail fin. “It’s started to heal under your skin. I have a local anesthetic with me, but I am going to have to break skin to get this out. If I’m being honest, I would much rather you come to my office, where I can treat this and the rest of your injuries much more thoroughly. I know they’re already healing, but some of the smaller cuts look infected and if they are, I worry about the bigger ones too. How long have you been here?”

“A few days,” Killua said. He didn’t want to go somewhere he’d be trapped on land. “If you could just get rid of the netting, I’ll be fine.”

“Are you sure?” It was the human boy, he leaning up on the edge of the rock, still half in the water.

Killua nodded. “I’d rather not be stuck on land.”

“Oh, you wouldn’t be,” Marina said. “I’m sorry, I should have been more clear, my office is right on the water, we only bring merrows inside if they’re seriously injured and unable to care for themselves. I have an outdoor set up specifically for situations like this.”

“Do you have injured merrows showing up often then?” Killua snapped. If this was standard, then it was likely the humans of the area were responsible for many of the merrow injuries.

“I wouldn’t say often,” Marina said. “But we have a standing arrangement with several local merrow communities, they assist our fishermen, give us advance warning of storms and we help their communities by providing medical care. I’m a wildlife vet and working with magical beast communities, when I am able, is part of that.”

“Fine…” Killua said. “We can go back to your office. How do I get there?” If it was really a safe place for him to recover he’d take it. If he caught wind that Illumi was after him, he’d still have room to hightail it, but for now the ability to stay near land and away from big ocean predators was the more ideal situation.

“I can take you,” the boy said. “It’s right next to the dock’s where the fishing boats go out.”

Killua wasn’t sure he liked that placement, but he also doubted an island this size would _have_ the really huge fishing boats like the one he'd been caught by. He slipped back into the water. “Lead the way, I suppose.”

“Great, see you in a bit Marina,” the boy said, pushing off the rock. “Hey, why don’t we race!”

Killua rolled his eyes. “I’m pretty sure I’d win.”

Killua did win, but the human had done a decent job of keeping pace with him. He had also been holding back because he couldn’t get too far ahead, since the boy was supposed to be leading and Killua didn’t really know where he was going.

“I told you I’d win,” Killua said, though he was grinning as he swam up to the beach where Marina was waiting for them.

The human grinned right back, “And you were holding back too, so you must be able to go really fast.”

“On a good day, I can move faster than your eye can follow,” Killua said. It wasn’t a brag, really, it was true, but there was a small part of him that very much wanted this odd human with poor self preservation skills to like him.

“Woah.”

The boy looked practically starry eyed and Killua could feel himself turning red, so he hauled himself out of the water and onto the tarp that Marina had laid out on the ground.

Getting treated wasn’t so bad, Marina was liberal with her use of local anesthetic, so instead of pain, Killua now just had weird numb patches all over his tail. She’d instructed him not to venture out too much until the anesthesia wore off, which Killua didn’t like, but he understood the reasoning behind it. Not properly feeling an injured spot increasing the risk of re-injury and all that.

“So you’re gonna be sticking around?” The boy asked, climbing out of the water just as Killua was sliding back in.

“For a little while,” Killua said.

“Cool. I’m Gon, by the way.”

“Killua.”

Gon held out his hand, “Nice to meet you.”

Killua just stared at him confused.

“Huh.” Gon dropped his hand. “So I guess handshakes aren’t a thing where you’re from.”

“I’m from a very insular community,” Killua said. It wasn’t a lie, he just didn’t need to know about the intricacy of human interaction in order to kill them. He didn’t want to kill Gon though, he _liked_ Gon.

Gon nodded. “That would explain why I haven’t seen you around before. I would have remembered you if I had, you’re very distinctive. The merrows in this area tend to be really vibrantly colored.”

“I'm from a family of whale merrows,” Killua said. “So we’re variations of black, blue and white.”

“Woah, so are you gonna get really big then?”

Killua shrugged. “I don’t really know, my dad’s pretty big, but my grandpa isn’t so much. We’re pretty mixed when it comes to size.”

“Do you have a big family?”

“Big enough,” Killua said. “Too many brothers.”

“I’m an only child,” Gon said. “I don’t know how I’d feel about having a sibling.”

“One isn’t so bad,” Killua said. “But the more you have the worse it gets, especially if you’re in the middle.” It wasn’t being in the middle that was Killua’s problem, but he wasn’t quite ready to explain the whole heir to a family of merrow assassins thing.

Gon scrunched up his face in thought; it was surprisingly endearing.After a few moments Gon spoke. “I’ve decided I’m going to show you around the island.”

Killua wasn’t sure how that subject change had happened, but it felt nice to be the center of nice attention of someone he actually liked. He sunk further into the water so it covered the bottom half of his face to hide his smile.

“I’ll get Aunt Mito’s wash bin and- uh oh…” Gon’s face fell, just a hair.

Killua popped up again, immediately concerned for his new friend. “What is it?”

“It’s nothing.” Gon scratched the back of his head sheepishly. “I just got in trouble for sneaking out last night and my aunt said I was grounded after I got back from helping you, so that tour of the island might not happen today.”

“I’ll be around for more than just today,” Killua said. “I have to stay around until the anesthesia wears off my tail.”

That had Gon brightening up again. “Great! I won’t be grounded for long I’m sure.”

* * *

Extra chores for the week was barely being grounded all things considered. He still had plenty of time to visit Killua by the water, though not quite enough to give him a proper tour of the island. By the time the week ended Gon was getting a little antsy, Killua could be leaving any day now, andwhileGon didn’t think Killua would leave without saying goodbye, he didn’t want Killua to leave at all.

The morning he was released from extra chore duty, Gon set about what he’d been planning all week. Design something that he could use to haul Killua around the island. It seemed unfair to just have him sit in a wagon, it would be uncomfortable and dry. Gon wanted Killua to have _fun_ and Gon was sure he wouldn’t if his still healing tail got all dried out.

What Gon dragged along with him to the beach when he went to see Killua a few hours later was Aunt Mito’s big old wash tub affixed to some wheels and a sturdy rope.

Killua stared at the wheeled contraption as Gon dragged it up.

“Today I’m taking you on a tour of the island!” He announced.

Killua frowned. “When you said that before I assumed you meant taking me alongthe coast, not… bringing me inland.”

“If you don’t want to that’s okay, I can definitely just take you around the coast, but I was thinking we could go inland, yeah,” Gon said. “I thought we could fill this with water so you wouldn’t get all dried out.”

Killua looked at the cobbled together cart again. “Oh, that makes more sense. Are you sure you’ll be able to pull me?”

Gon beamed, very relieved that he had messed up. “Yup! I mean we’ll still go slow, but pulling you won’t be an issue.”

“Let’s go then,” Killua said, grinning.

Killua’s grin made Gon’s stomach do a weird flip. He decided to ignore it and just focus on getting the wash tub full of water.

“So, I’m assuming this island has a name,” Killua said, as he and Gon headed away from the beach.

“Yeah, its called Whale Island, cause it’s shaped like a big whale. It’s kind of hard to see when you’re on it though.” Gon paused in pulling Killua when they reached the bottom of the incline that would take them up away from the water.

Killua’s knuckles were white with how tight he was gripping the edge of the tub.

Gon frowned. “Are you sure you’re comfortable doing this?”

Killua tensed like he’d been caught at something. “I’ll be fine, this is just the first time I’ve done anything like this.”

“Hmmm, I suppose that’s fair,” Gon said. “I’m going to push you up the hill, it’ll probably be safer.” The last thing Gon wanted was for the rope to snap, but if Gon was pushing Killua that risk could be avoided.

Killua nodded and resettled himself in the wash tub before Gon began pushing him up the hill.

Gon haddecided it was for the best to keep Killua away from the town center, so the route he took them up by was the way that would take them to the forest instead ofthe town. It was a bumpier climb and they lost some water in the process,but Gon thought it was totally worth it when he saw Killua’s face when they reach the top.

“Any first thoughts?”

“It’s prettier than I expected,” Killua said. “I mean, I saw the trees and stuff by the lagoon, but this is… bigger. The kelp forests I’m used to aren’t… they aren’t…. kelp doesn’t get that big.”

“Yeah, you can’t climb kelp either,” Gon said. He moved around to startpulling the make-shift wagon instead of pushing it. “I’ve fallen asleep up in tree more than once.”

Killua grinned. “That seems like something you’d do.”

Once again, Gon’s stomach did weird things. He had a split second thought wondering if this was what “butterflies” felt like, but his thoughts switched back to exploring with Killua immediately.

“I’m good at being still and quite so I don’t bother the animals living there.”

“Like how you were able to sit and watch me for almost a week without me being able to find you,” Killua said.

Gon stopped again once they were in the shade. “You knew I was there?”

Killua shrugged. “I knew something was watching me, but I wasn’t really worried about it, you didn’t seem at all that threatening until you grabbed me.”

Gon flushed. “Sorry. I couldn’t think of a better way to get yourattention without scaring you off!”

“Well I think it all turned out okay,” Killua said. Then a little hesitantly he added. “We’re friends now, right?”

Gon beamed. “Yeah definitely! Come on, I want toyou to meet someone, his name’s Kon, he’s a foxbear. I raised him from a cub.”

* * *

Killua was a little concerned about ocean predator meets land predator, but in the end there was nothing to worry about. Kon was perfectly content to co-exist alongside Killua, though Killua wasn’t sure that he would want to try doing it without Gon there as an intermediary.

Still, it was nice to spend the day getting to explore a place he never would have been able to on his own.

They stayed out for most of the day, refilling Killua’s tub from freshwater springs and rivers when the water level got too low and stopping every once and a while when Gon needed a break.

Killua also tried a number of foods that he’d never had before. Gon made him try a number of different berries that they came across and Killua found he quite enjoyed the sweeter ones. He was finding more and more reasons to want to stay near the island instead of moving on.

Gon also brought Killua to his home when it was getting near lunch time and Killua was surprised to find that Gon’s aunt had prepared lunch for him too. Killua had never really considered what it would be like to eat fish that had already had the bones removed. He found he missed the crunch.

When they made it back down to the ocean, Killua felt surprisingly sad that the day was over. He wanted to spend more time with Gon.

“So where are you going to go next?” Gon asked as he pushed the cart into the water so Killua could slide right out.

Killua submerged briefly before popping back up to answer. “I don’t know, I mean I hadn’t really had a concrete destination when I left home, but… I think I might stick around here for while. It’s nice here.”

_You’re nice_. He wanted to say, but just the thought of actually saying that out loud was enough to make him flush. He was grateful it was dark.

The smile that appeared on Gon’s face was enough make Killua’s stomach swirl with anxiety and something that was possibly, maybe, falling just a bit in love with Gon. He was just so happy and enthusiastic and caring. Killua couldn’t imagine anyone _not_ beingdrawn to that. He was so lost in his thoughts that he didn’t realize that Gon had said something until Gon waved a hand in front of Killua’sface.

“Sorry, I got lost in my head I guess.”

Gon laughed. “It’s okay, I just said I’m glad you’re gonna stay longer. I really like hanging out with you.”

“Oh. I, uh, I really like hanging out with you too. Today was really fun. I wish those berries you had me try grew down here, they were really good.”

“Well, I’ll just have to bring you more then!”

Killua was quiet. It was a small declaration, sure, but it _felt_ overwhelming. Gon really didn’t have to do that, but he acted like it was a given that he would.

“I actually have a question about merrow stuff,” Gon said. Sitting downin the surf.

Killua swam closer so that he was lying on the beach near Gon’s feet, but still in the water enough so that he wouldn’t get stuck on the sand.

“Aunt Mito said she’d heard an old wives tale that if a merrow kissed you, then that would turn you into a merrow too.”

Killua was suddenly very glad it was dark and that Gon wouldn’t be able to see just how red he’d turned.

“I don’t know if that’s true,” he said. He’d never been one to care much about human merrow myths, not like Illumi who kept a growing catalogue so he could better ensnare his victims.

“Hmmm,” Gon wrapped his arms around his legs and rested his chin on his knees. “I was just thinking about ways that you could show me around the ocean like I showed you around on land.I could go out on a boat, but that’s not really the same thing.”

Killua wasn’t sure what possessed him to respond the way he did, but the next words out of his mouth were: “Well, I don’t think it would hurt to try.”

He immediately clamped a hand over his mouth and his face started to burn from what was possibly the most horrific embarrassment he’d ever felt in his short life.

Gon, looked equally flabbergasted at the suggestion and he opened and closed his mouth a few times, but never actually said anything.

Now was the time to slide into the water and disappear, Killua thought. Slink back into the ocean and never look back, he was healed well enough, he’d be fine.

He must have started inching his was back into the water, because the next thing he registered was Gon grabbing his wrist and then sitting back down with a splash in much deeper water than they were previously in.

“Please don’t run away,” Gon said softly. “I- you just surprised me is all. If you want to try, I’d be okay with that.”

Part of Killua’s mind was still screaming to flee into the ocean, but… if Gon was okay with the idea then maybe it wouldn’t be so bad? And he really did want to stay and continue being Gon’s friend.

Gon let go of Killua’s wrist and Killua pulled himself up to sit next to him. Fixing the thought in his mind that he was just doing this to see if Gon would grow a tail, Killua leaned in and pressed a quick kiss to Gon’s cheek, squeezing his eyes shut as he did so.

Killua felt a cold rush like electricity run through him and then there was a flash followed by a ripping noise and a startled exclamation from Gon.

“Killua it worked!”

Killua’s eyes snapped open. Sure enough, where Gon’s legs had been was now a shimmering blue green fin. Of course Gon would be something shiny and tropical looking.

Gon flicked his tail a few times in the water and then Killua noticed Gon’s shorts. They’d gotten torn off and were now floating in the water.Killua grabbed them before they could float away.

“Thanks,” Gon looked at them and frowned. “I probably should have taken these off first. I am still going to need to them to get home.”

A horrific realization dawned on Killua. “We need to figure out how to get you switched back first. You can’t just…” He gestured to Gon’s new-made fin.

“Try kissing me again, but I don’t know, trying thinking about turning me back or something?”

Killua swallowed heavily, but did as Gon suggested and with another flash Gon had legs again.

Gon shimmied back into his shorts. They weren’t totally ruined, but Killua doubted they’d be able to be repaired.

“I should probably head home,” Gon said. “I don’t want to get in trouble with Aunt Mito again, but I’ll come back tomorrow and you can take me on an underwater tour then!”

After saying goodnight and deciding that they would meet at the lagoon tomorrow instead of the beach, Killua watched as Gon ran up the beach and towards home. Once Killua couldn't see Gon anymore, he disappeared under the water. 

_Holy shit_ , that had really just happened. He just kissed Gon, _twice!_ Sure it had been a completely platonic experiment to see whether or not it would turn Gon into a merrow, but still. If he had been even slightly unsure before, Killua was now one hundred percent certain that he had a crush on Gon.

Killua really didn’t get much sleep that night as his mind kept racing with thoughts of what might happen the next day. Gon had never been underwater before and more than that, Gon would have a freedom of movement that Killua hadn’t being toted around in a wagon full of water.

He must have fallen asleep at some point, however, because he was woken by large splash in the lagoon just as the light was starting to stream into his cave. He panicked for a momentbefore he realized it was probably Gon and he stretched and swam out to meet him.

Gon beamed when he saw Killua come up. “Killua!”

Killua grinned back. “You ready?”

Gon nodded, and Killua noticed the pile of clothes sitting at the water’s edge.

Quick as a dart, and with the same thoughts in mind as the night before, Killua pressed a quick kiss to Gon’s cheek and then disappeared underwater, mostly so that Gon’s wouldn’t see him flush, but also he wanted to see what Gon would do.

As Killua had hoped, after only a moment’s delay, Gon dove down after him. 

**Author's Note:**

> The title is from the children's book "Kiss of the Mermaid" in Mercer Mayer's "Critters of the Night" series. It was a fave of mine when I was a kid.


End file.
